Varicose veins are blood vessels that have become twisted and swollen when their one-way valves are compromised or when the vein wall weakens. As people grow older, the likelihood of having large and/or smaller varicose and spider veins increases. In fact, varicose and spider veins affect over half the population by age 55 and is linked to factors such as heredity, pregnancy, estrogen medications, prolonged standing or sitting, sedentary lifestyle, and injury to the legs. Left untreated, varicose veins can cause pain, swelling, phlebitis, chronic skin ulcers, and potentially life-threatening blood clots. Unsightly and embarrassing spider veins, on the other hand, are not dangerous and are simply enlarged venules.
Though benign, many individuals desire treatment of spider veins because of their appearance. Traditional treatment has consisted of sclerotherapy, which involves injecting a small amount of a mild sclerosing solution into the affected veins. Many different kinds of chemical solutions have been used for this purpose, including hypertonic sodium chloride, sodium morrhuate, sodium tetradecyl sulfate, Polilocanol, Sclerodex-Dextroject, Chromated glycerin and Polyiodide Iodine to name a few. Treated veins gradually disappear over one to six months. It frequently takes several sessions to provide the most effective results. Unfortunately, sclerotherapy treatments are not effective for larger varicose veins, which require more aggressive treatment.
Another approach is to obliterate the spider veins directly with the laser. Although this treatment can be successful, there is a significant risk of scarring. In addition, the equipment is very expensive.
An illustrative example of conventional solutions to the limitations of first-generation treatments is disclosed in U.S. Pat. No. 5,695,495 to Ellman. The '495 patent discloses an electrode for use in an electrosurgical procedure for treating varicose veins. The invention disclosed in the '495 patent is impractical in theory and inoperable in practice. Moreover, the disclosure itself has inherent limitations. One principal limitation is that the needle must be introduced into the target vein to be effective. In fact, the needle with an insulating coating is inserted into the target vein, resulting in increased invasiveness and diminished accuracy. An additional limitation is the fact that the insulation stops short of the needle tip, resulting in increased collateral tissue damage. Moreover, because of the active tip configuration, it is difficult to control the dispersion of the electrical charge. This is a function, inter alia, of an available electrical current throughout the non-insulated area. Without extraordinary skill, a physician that uses such a device could cause significant tissue damage around the target vein.
Therefore, there exists a need for a relatively inexpensive micro-invasive procedure for treating spider veins. Moreover, there is an existing need for a device that can destroy the target veins without causing collateral damage to neighboring tissue. Preferably, an exemplary device would have an ultra thin insulating sheath that is substantially co-terminal with the active tip, wherein the active tip does not have to penetrate the target tissue. Moreover, it would also be desirable if the active tip of the device were beveled at an acute angle to maximize physician control and working surface area while reducing collateral tissue damage.